Bundling or gripping device



July 6, 1943. J. G. LEWIS BUNDLING OR GRIPPING DEVICE Filed March 25, 1942 4 Sheets-Sheet l 5 MM N Sam ml 7 T 9 ,6 A J m 0 M w 5% 0/H M r WYD L, & Cl 5 July 6, 1943. J, w 5 2,323,819

BUNDLING OR GRIPPING DEVICE Filed March 25, 1942 4 Sheets-Sheet 2 #7 TORNE 6 July 6, 1943- gw s 2,323,819

BUNDLING OR GRIPPING DEVICE Filed March 25, 1942 4 Sheets5heet 3 /N VENTOR July 6, 1943. J w s I 2,323,819

BUNDLING-OR GRIPPING DEVICE Filed March 25, 1942 4 Sheets-Sheet 4 M3 M4 M M M5 M M INVENTOR ATTORNEYS Patented July 6, 1943 BUNDLING 0E GRIPPING DEVICE James Gabriel Lewis, Sunderland, England, assignor to Iyrotenax Limited, Hebburn-on- Tyne, England, a company of Great Britain Application March 25, 1942, Serial No. 436,191 in Great Britain March 26, 194.1

13 Claims.

' coils of wire or unbound bundles of rods or tubes or the like without the use of slings. The device according to the invention may however be used for other purposes, for example generally for forming a compact bundle of wire, rods, tubes or other articles from a loose stack, or for operating the fingers of artificial hands.

The bundling or gripping device according to the present invention comprises two interconnected chains of pivoted links of which the intermediate links each have three pivots in triangular formation and cooperate with one another to form in effect a sequence of crossed four-bar linkages, and means for imparting relative movement to the end links of the two chains at one end whereby a change of angles will be transmitted through the sequence of linkages and the pair of chains as a whole will be caused to assume a spiral formation.

Conveniently, two of the pivots of each intermediate link constitutethe connections to the adjacent links in the same chain and the third constitutes the interconnection to the corresponding link of the other chain, each such third pivot being common to two consecutive fourbar linkages. The end link of one chain is preferably pivoted to a supporting member, while an actuating member is provided to move the end link of the second chain relatively to the supporting member. Such actuating member may conveniently be in the form of a lever pivoted to the supporting member and to the end link of the second chain.

When the device is applied to cranes or other lifting gear, the supporting member is conveniently constituted by a suspended hook, from which the pair of chains extends in such a manner that the weight of the load gripped in its curled-up position is taken mainly or wholly by the hook. The actuating member may be so connected to the support from which the hook is suspended that the weight of the load on the hook tends to hold the pair of chains in its curledup position. The actuating member is conveniently so weighted or spring-controlled as to tend to cause the pair of chains to straighten out ,when the hook is unloaded.

It will usually be preferable so to arrange the links that, in one of its positions, the pair of chains will be more or less straight. The triangles formed by the pivots of the intermediate links may all be similar to one another, the angular change in the linkages between any two positions being the same throughout the length of the pair of chains. Alternatively the arrangement may be such that the angular change in the linkages between any two positions progressively varies from one end of the pair of chains to the other.

The invention may be carried into practice in various ways, but some convenient practical constructions according thereto for use on a crane or like lifting gear are illustrated by way of example in the accompanying drawings, in which Figures 1 and 2 are side elevations of a preeferred construction of the device respectively in two different operative positions,

Figure 3 is a horizontal section on the line 33 of Figure 1,

Figures 4 and 5 are partial views showing the two chains separately,

Figures 6 and '7 are diagrams illustrating the operation of the device and associated respectively with the positions of Figures 1 and 2,

Figures '8 and 9 are respectively an elevation and a plan of a modified form of link, and

Figures 10, 11 and 12 are diagrammatic views resembling Figures 1-3 of an alternative construction.

In the construction of Figures 1-7 the device comprises two chains A and B of triangular links (shown respectively in Figures 4 and 5) interconnected with one another and extending from a hook C suitably suspended from the crane or other lifting gear. The triangular links are all of equal size and shape and in one convenient arrangement (as shown) each is in the form of an obtuse-angled triangle with the side opposite the larger acute angle uppermost. The links A A A of the first chain A have their sharpest corners pointing in one direction, say away from the hook C, and links B B B of the second chain B have their sharpest corners pointing in the opposite direction towards the hook C.

Each link has three pivot points at its corners and the sharpest corner is pivoted to the obtuse angled corner of the next link in the same chain, whilst its lowermost corner (the larger acute angle) is pivoted to the corresponding corner of the associated link in the other chain. With this arrangement, there will be one position of the pair of chains A B, in which the uppermost sides (0pposite the larger acute angle in each case) of all the links in both chains lie in a single plane extending more or less horizontally or slightly upwardly from the hook C, preferably approximately tangentially to the curve of the hook at the toe,

and this position (which is shown in Figure 1), will, for convenience of description, be referred to as the normal position of the pair of chains.

The obtuse-angled corner of the first link A of the first chain A is pivoted at D to the toe of the hook C, with its sharpest corner pointing away from the hook and pivoted at D to the obtuse-angled corner of the second link A in that chain. The third corner of this first link A is pivoted at D to the corresponding corner of the first link B of the second chain B, which points across the hook itself and has its sharpest corner pivoted at D to an actuating member E, which is itself pivoted at E to the bottom end of the hook C. The line joining the two pivots D E of the actuating member E is equal in length to the shortest side of the links and in the normal position (Figure 1) lies parallel to the shortest sides of the links of the second chain B. The obtuse-angled corner of the first link B of the second chain B is pivoted at D to the sharpest corner of the second link B of that chain, and the obtuse-angled corner of such second link B is likewise pivoted at D to the third link B of the same chain. The remaining corner of the link 13 is pivoted at D to the second link A of the first chain A and the sharpest corner of such link A is pivoted at D to the obtuseangled corner of the third link A of the same chain, such third link A being pivoted at D to the third link 13 of the second chain. The example illustrated employs three links in each chain, but it will be appreciated that other numbers of links may be used.

The actuating member E may be of any convenient shape, but in one convenient form consists of an arm extending from the two pivots D E in a direction away from the length of the pair of chains. This arm may be spring-controlled or weighted at its free end, so as normally to be urged downwardly to bring the pair of chains into the normal straight position, a stop C being provided against, which the lower edge of the link B engages when such position is reached.

' With this arrangement the pair of chains forms in eifect a number of crossed four-bar linkages connected in sequence with one another by the links (as shown in Figures 6 and 7). Thus the first linkage is built up of the part of the actuating member E between its two pivots D E the longest side D D of the first link B of the second chain, the shortest side D D of the first link A of the first chain, and the line joining the two pivots D E on the hook. This linkage thus has two pairs of equal bars, the shorter equal first and third bars D E and D D being opposite to one another, whilst the longer equal second and fourth bars D D and D E cross one another. In the normal position, this linkage may be said somewhat to resemble the letter W.

When the actuating member E is raised from its normal position the first bar D E of the linkage will swing about its fixed pivot E on the hook, and since the fourth bar D E is fixed to the hook, the second and third bars will be positively moved to change the angles of the linkage, which thus moves from its normal W-shape into its operative position wherein it resembles the letter M. In this operative position the shortest side D D of the first link B of the second chain may be more or less superimposed on the shortest side D D of the first link A of the first chain.

The second four-bar linkage in the sequence comprises the shortest side D D of the first link B of the second chain, the longest side D D of the second link B of the second chain, the shortest side D D of the second link A of the first chain, and the longest side D D of the first link A of the first chain. This linkage is precisely similar to the first, and has the junction of its first and fourth bars pivoted at D to the junction of the second and third bars of the first linkage. Its first bar D D is rigidly connected by the first link B of the second chain to the second bar D D of the first linkage, and its fourth bar D D is rigidly connected by the first link A of the first chain to the third bar D D of the first linkage. Thus the two driven bars of the first linkage are rigidly connected to the two driving bars of the second linkage, and this continues throughout the sequence of linkages, the first and fourth bars of each linkage constituting the driving bars and the second and third the driven bars.

The angular change in the first linkage is thus transmitted equally from linkage to linkage. In the normal position the W-shaped linkages lie in line with one another and overlap (with one bottom corner in common between each pair of consecutive linkages) and in the operative position the linkages all take up the M-shape with their sides more or less superimposed, so that the whole chain curls up. In this curled-up operative position the sides of the links opposite the large acute angles (that is the sides which are coplanar in the normal position) extend in sequence at the same angle to one another after the manner of the sides of an incomplete regular polygon.

While, to simplify the description, this particular curled-up position has been described as the operative position, it will be clear that in practice all the curled-up positions are equally operative positions and the actuating arm E will be moved far enough to grip the particular load. A second stop D may be provided to prevent the chains from curling up far enough to foul the hook or the beginning of the chains. Thus, for example, if the load consists of a loose group of rods or tubes from a stack, the free end of the pair of chains (consisting of the sharpest corner of the last link A of the first chain) is pushed underneath the group of rods, and operation of the actuating arm E causes the pair of chains to curl up round the rods until it grips them firmly, As it does so, it will move the rods on to the hook C itself, so that the weight will be taken mainly by the hook and the pair of chains will serve primarily to hold the bundle firmly against the hook.

The arrangement may be such that, when the hook is loaded, the weight of the load on the hook tends to urge the pair of chains more tightly into the curled-up position, thereby ensuring a tight grip on the load. This may conveniently be effected by suspending the actuating member E, rather than the hook C itself, directly from the crane or other lifting gear, so that the hook C is carried by the actuating member E, through the pivot E at the base with a suitable pivoted link connection F at the upper end of the hook body to prevent tilting of the hook relatively to the suspension members G G Thus the weight of the load on the hook C will tend to cause the hook to move downwards, and therefore the actuating arm E to move upwards relatively to the hook thus urging the pair of chains to curl up more tightly. The spring or counterweight on the actuating member if provided may then (if desired) be chosen to exert a force large enough to overcome the weight of the unloaded hook, so that the pair of chains would automatically straighten out when unloaded. Alternatively, if it is preferred to keep the chains curled up normally, an operating force to move the actuating arm E downwards (or the hook upwards relatively 'tothe'suspension) will be necessary to straighten out the chains preparatory to taking up a load. A handle H may be provided on the hook.

- While, for simplicity, in the foregoing description, each link has been assumed to consist of a single triangular plate, it will usually be preferable in practice to employ two or more plates interleaving with the plates of adjacent links. Thus in one convenient practical arrangement, as shown in Figure 3, the second chain B consists of alternate single-plate and two-plate links, with the single plate of the first link B engaging between two bars together constituting the actuating arm Eand also between the two plates of the second link 12 which in turn engage on either side of the third link B The first chain A may in this case conveniently be duplicated with its two parts one on either side of the second chain B, each part consisting of alternate two-plate and single-plate links. This arrangement not only afiords substantial thickness of the whole device to provide adequate surface area for holding the load, but also distributes the load more symmetrically on the hook, thus assisting to prevent lateral tilting of the hook when loaded It may also be convenient in some instances to interleave plates of the first chain with plates of the second chain. Again it is not essential to employ triangular plates, and each link may be built up (as shown in Figures 8 and 9) of a group of three simple straight bars J J J in triangular formation. In this modification each straight bar may be constituted by a set of two or more bars interleaving with the other bars.

Although the device has been described as having a normal straight position and as curling up therefrom to any of its operative positions, this arrangement may be varied as desired. Thus for some uses it may be more convenient for the device to curl downwards from a normal straight position, Again it is not essential for the device to have a straight position. The shapes of the triangles can be varied, as desired, and it may often be more convenient to employ triangles of different shapes and sizes. Thus to facilitate interleaving of the two chains, it may be convenient to employ one shape for the links of one chain and a difierent shape for those of the other chain, or again alternate links in each chain may be of different shape from the remaining links in the chain. The shapes and sizes of the triangles may vary from one end to the other of the pair of chains, for example to give greater curvature of the device at the outer end than at the inner end or vice versa.

One example of such modifications is illustrated in Figures 10-12. In this alternative conthe link K is pivoted at M to the corresponding corner of the first link L of the second chain, which points across the hook N and isupivoted at its sharpest corner at M to the actuating member 0, which is itself pivoted at O to the hook N. The arrangement of the hook N and actuating member, is, similar to that .of the previous construction.

The obtuse-angled corner of the first link L of the second chain is pivoted at M to the sharpest corner of the second link L whose obtuse-angled corner is pivoted at M to the sharpest corner of the third link L of the same chain. The remaining corner of the second link L of the second chain is pivoted at M to the second link K of the first chain, Whose sharpest corner is pivoted at M to the obtuse-angled corner of the third link K of the same chain. Such third link K is pivoted at M to the third link L of the second chain and has its sharpest corner pivoted at M to the obtuse-angled corner of the fourth link K of the first chain. The fourth link L of the second chain is here shown as consisting merely of a straight bar pivoted at its ends at M and M respectively to the third link L of the second chain and to the fourth link K of the first chain, since the remaining portion of the trian le happens here to be unnecessary.

The links of both chains progressively decrease in size from the hook outwards with consequent progressive change in angular movement. In order to prevent fouling of the various links by the pivots, slots P and P are cut in the hook N respectively for the pivots M and M a slot P is cut in the hook K for the pivot M a slot P is cut in the link L for the pivot M and a slot P is cut in the link K for the pivot M The links K and K consist of single-plates. while all the other links (as well as the hook N and the actuating member 0) are duplicated. The double link L interleaves between the links K and K and the double link K likewise inter leaves between the links L and L Such inter F leaving tends to reduce the maximum bending struction the shapes of the links vary progresmoment on the pivot pins.

It will be appreciated that the device according to the invention may be employed for purposes other than the handling of loose bundles of articles by lifting gear. For example, it will be at once clear that it is suitable for use in picking up loose articles from a stack and forming them into a compact bundle ready for tying up. Another use for the device is for the operation of the fingers of an artificial hand, to enable the fingers to be caused by appropriate muscular action or otherwise to close round any article it is desired to grip.

What I claim as my invention and desire to secure by Letters Patent is:

1. A bundling or gripping device, comprising two interconnected chains of pivoted links, of which the intermediate links each have three pivots in triangular formation and cooperate with one another to form in eifect a sequence of crossed four-bar-linkages, and pivoted means for imparting relative movement to the end links of the two chains at one end whereby a change of angles will be transrm'tted through the sequence of linkages and the pairs of chains as a whole will be caused to assume a spiral forma tion.

2. A bundling or gripping device, comprising two interconnected chains of pivoted links, of which each intermediate link has three pivots in triangular formation, two of such pivots constltuting the connections to the adjacent links in the same chain while the third constitutes the interconnection to the corresponding link of the other chain, whereby the links cooperate with one another to form in effect a sequence of crossed four-bar linkages, a supporting member to which the end link of one chain is pivoted, stop means for holding the device in normal position and an actuating member for moving the corresponding end link of the other chain relatively to the supporting member whereby a change of angles will be transmitted through the sequence of linkages and the two chains as a whole will be caused to assume a spiral formation.

3. A bundling or gripping device as claimed in claim 2, in which the actuating member is in the form of a lever pivoted to the supporting member and to the end link of the second chain.

4. A bundling or gripping device as claimed in claim 2, in which the supporting member is in the form of a suspended hook from the toe of which the pair of chains extends, the arrangement being such that in the curled-up position of the chains the weight of the load gripped is taken at least mainly by the hook.

5. A bundling or gripping device, comprising two interconnected chains of pivoted links, of which each intermediate link has three pivots in triangular formation, two of such pivots constituting the connections to the adjacent links in the same chain while the third constitutes the interconnection to the corresponding link of the other chain, whereby the links cooperate with one another to form in effect a sequence of crossed four-bar linkages, a supporting member in the form of a suspended hook to the toe of which the end link of the first chain is pivoted, and an actuating lever pivoted to the hook and to the end link of the second chain, whereby a change of angles will be transmitted through a sequence of linkages and the two chains as a whole will be caused to assume a spiral formation.

6. A bundling or gripping device as claimed in claim 5, in which the suspension of the hook is efiected through the actuating lever, whereby the weight of the hook and the load thereon tends to hold the pair of chains in the curled-up position.

7. A bundling or gripping device as claimed in claim 5, in which the relative weights of the parts of the device and the positions of the pivots are such as to tend to cause the pair of chains to straighten out when unloaded.

8. A bundling or gripping device as claimed in claim 1, in which the links of the chains are in the form of fiat plates, at least one of the links consisting of a plurality of plates connected togather by the three pivots of the link and having the associated link plates disposed between them.

9. A bundling or gripping device, as claimed in claim 1, in which the links of the chains are in the form of generally triangular fiat plates, at least some of the links consisting of pluralities of plates interleaving with the plates of associated links.

10. A bundling or gripping device as claimed in claim 1, in which the triangles formed by the pivots of the intermediate links are all similar to one another and of the same size, whereby the angular change in the linkages between any two positions of the pair of chains is the same throughout the length of the pair of chains.

11. A bundling or gripping device as claimed in claim 5, in which the triangles formed by the pivots of the intermediate links are all similar to one another and of the same size, whereby the angular change in the linkages between any two positions of the pair of chains is the same throughout the length of the pair of chains.

12. A bundling or gripping device as claimed in claim 1, in which the dimensions of the triangles formed by the pivots of the intermediate links vary along the length of the pair of chains, whereby the angular change in the linkages between any two positions of the pair of chains varies progressively from one end of the pair of chains to the other.

13. A bundling or gripping device as claimed in claim 5, in which the dimensions of the triangles formed by the pivots of the intermediate links vary along the length of the pair of chains, whereby the angular change in the linkages between any two positions of the pair of chains varies progressively from one end or" the pair of chains to the other.

JAMES GABRIEL LEWIS. 

